I really shouldn't need to explain this. More famous doesn't equal better, yes, they may be more critically acclaimed, but that does not mean that their music is better only because they have more views on Youtube.
Also, in the modern age of this industry, we tend to imagine that we as people are responsible for who gets famous, but there are so many games behind the scenes that nobody becomes famous without a reason, especially when we're talking mainstream fame. And no, I'm not only talking about the games that labels play - buying spots on the radio, having a different platform where they can pitch music to Spotify, millions upon millions of dollars in marketing, venue placement and all that good shit, I'm also talking about Spotify and Youtube algorhythms that work for people who are already ahead, not for emerging artists, and especially not for artists that are not coming from a country that's a major player in the music soundscape. Basically, more and more nowadays you're listening to what's put in front of you, and rarely do you look for ways to seek out music on your own, this was made apparent by Spotify and how people consume music through playlists and are not even listening to full albums most of the time.
Artists like Avicii don't come out of nowhere, artists nowadays are massively produced and the labels paint a pretty picture to make you think they're hot and up and coming, but everything is planned out years in advance. You could see that by looking at credits and seeing what songwriters wrote songs for who and then went on to become famous artists themselves after years of grind in the industry making connections, oooor another good example would be a huge super star Taylor Swift having a huge tour and who is warming up the stage for her? Shawn Mendes, Troye Sivan, Fifth Harmony that were put there by their labels and are now all huge artists.
Lenny never had the chance to become more famous than Avicii, does that mean that she should automatically lose to him? ABSOLUTELY NOT.